[tom hyle]

Of the ones that really are cermonial, some are rank markers for traditional government officials (ie "chiefs" etc.) and are borne by them or their sword bearers for civil (or now usually tribal, the traditional governments having mostly given way to "Western" style federal beaurocracies in at least some degree) occasions and ceremonies. Many are used as "fetishes"; conduits/summoning devices for devine/supernatural/dead beings/persons. I hadn't heard of them being used to attack such beings before, but it makes sense in terms of the customs of other cultures and my own interactions with such beings; they can be frightened of a sword. Some may be used for animal sacrifice, though I've seen that done ordinary knives/swords. Others may be used in scarification ceremonies, though now days one hears of those being done with broken bottles or whatever other blades; I imagine that traditionally there'd've been particular blades.